 All right. Well, thank you. So having being the last person is always sort of, you know, it's odd, you either going to be the person before lunch or the last person. So, so today you got the last person. So, but one of my I went friends was the last one before lunch. So that's so there we go. So what we're going to talk about a little bit is so washing so flushing you can either call it active and passive. And I think bringing up some of the points of where it might work where it may not work. I think is is a useful sort of exercise. So Chris Knox will come up and he needs about the eight to 10 minutes towards the end. So we'll we'll we'll get moving on here. No, not personal support. Thank you very much. So one of the things that we we we try to think about and and thinking about like the end product. You know, I mentioned before the landowner the land use soil function at the end of the day. A lot of these things that we think about need to be incorporated into our remediation or reclamation because things that happen on the front end will have long term consequences for the landowner down the road. So So thinking like what physical properties, so biological properties, so chemical properties, all of these need to be thought about before you can start thinking about soil function and quality. So all health is a word that that gets used a lot to which ends whether it's range land productivity or crop yield. So when we hopefully when we think about these reclamation projects we try to keep all these into the back of our head at least or towards the forefront. So I came up with this sort of a conceptual model of thinking about like, you know, if you think about liabilities, you have liabilities from the landowner, their mental liability you have the responsible company they have liability. The state has liability because they're going to be monitoring the site for long periods of time so part of it is like how do you reduce the amount of liability over time. And so, thinking about like relative recovery where one meaning that it's back to sort of where it was when it when it started. But then you have this time from the incident and you have this the trajectory or the slope will be dictated by what method you choose or what method is is is thought about. For example, the dig and haul method which is happening very quickly, that has a very steep trajectory, but compared to the do nothing might take a long period of time so that liability gets drug out from over a long period of time. And so but some of these other things, electro kinetics, phyto remediation so washing so flushing, we don't have a maybe a good handle on where that where that slope is. And so that's what I'm trying to get at is is when we think about it from a conceptual standpoint it's not always just about using this method but it's like the time of relative recovery in that thinking about that that liability. So washing versus flushing. So this is my dog, Ellie, who apparently had a rough night last night. But so one of the things we like to think about it is that, you know, are you going to be washing the soil per se, are you just going to be trying to reduce the amount of disturbance and try to flush things out. And these are also called active and passive respectively. So thanks to Beverly she she made this for me. So washing is more about the concepts of removal, moving it through an area washing it through and then putting it back. Okay, so, and then the, and then the whatever the contaminant might be being brought to a disposal of facility in some sort of proper way. And so it might look like this. And then the conceptual models. There's two articles that I found like very helpful. And they were from our, the EPA, one of them was a citizen's guide to soul washing. And the other ones a citizen's guide to soul flushing. And you know, to even have those available for just to read, I thought was fairly worthwhile. But here you have the contaminated soil you got a washing solution you got soul washing then you have this clean soil on the on the backside. It's not unlike thermal where you would screen all the big rocks out, you would run it through the thermal disorber, you could use the product at the back end because it was hydrocarbon free. So, so again, sort of a washing process. There's another a conceptual sort of diagram on that. But some of the things that you can about imagine is these pros and cons. And so the requires excavation and results in very, very high soil disturbance. And that's one of the things that is very, it's talked about a lot is that there's no structure left after the washing, because of the fact that it gets moved around so much water gets moved through, or it gets sort of filtered out quite a bit. Everything I read, it's best in low clay low silt course textured soils. And why is that water moves through sands and and silt's a lot easier than it does through claims. And we'll talk about the different clays, the different clay speculations in a minute. You're no doubt likely going to get some separation of sands from the silt and the clay. So whatever look like soil may not actually be that soil at the end of the day. The great thing about it, it's everything on sites. I mean, you can keep everything there, you can you can control your control your environment. We're going to talk about this again. We have a lot of snack tight or Montmorillon I clays in our soils, especially in the glaciated region and in the Red River Valley as an example. Non expanding clays like ili kale and I chloride water can move through those a little bit better because they don't swell up so much. Think about bent night bent night is a is a is an expanding clay right we use it for that reason to cap wells. Smack tight is not as expanding as bent night but it is an expanding clay. You would certainly never want to try any of this with on soils that are high in bent night, for certain. So the bell foosh area is pretty much out of the other question. Again, always do the delineation. Always figure out where your soils and geology are in the area. It does require a solution of course, because what you're trying to do again is mobilize that sodium and chloride, the main constituents in the brine in most of in most cases, we have found brine in North Dakota that is exceptionally low and sodium but very, very high in calcium. It was an oddity, I think but but but those do exist. You need a way to collect and dispose. You need water. And so the one thing that I think is important to remember with this, the washing is that you control the narrative. You are in control of what you dig out and what you wash and what you put back, which I think that is a is a bit different than when we think about the flushing the flushing because of the fact that you're not pulling out and knowing everything about it characterizing it. Yeah, you can do all the coring you want you can do all the sampling, but you're still at some mercy. You're still at some mercy of some environmental sort of conditions so here's just a you know a possible method. You can even think about this impact of soil as being in situ. And then you would put tile drain in and you would be able to flush that down through you of course need water. And in this case, I think having a source of calcium is paramount and we'll talk about why swelling soil dispersion and swelling occur in a minute. I really like this one. As an example it's in that citizens guide into in situ soil flushing, but basically you're sort of pushing water, you're pushing water towards that endpoint. And by doing that, you can about imagine trying to do this in a high clay soil, it's not going to go work out so well, but doing it in a coarse textured soil or soil with a fair amount of silt in it actually might not work too bad. And sort of in the same vein, you have this water coming from a different sides, if you will, but you have one pump in the middle and you're drawing everything out of that one area. So I think there's some good examples of how soil flushing can be utilized. I didn't go through these individually, but I only italicized the ones that were different from the soil washing. So the soil flushing, the ones that are different in situ, so the top soil is not disturbed as much as ex situ. So the soil washing where you would actually remove it, clean it and put it back. The other one is the you can't control the narrative as much. And I think that's a little bit of a wild card is that you're sort of at the mercy of the tools and the instrumentation, the geology a little bit. And so if in fact it needs to be done quickly and in a manner, the soil washing is probably a better way to go because of the fact that you are in full control. Other variables to consider. So back to our back to our clays, smectite, ilite, chloride, kaolinite. These will play a big part in whether or not you can move water through these systems. It doesn't take much smectite clay to keep water movement very restrictive. And so, but surprisingly, surprisingly, when I asked my two soil physics buddies at NC State and they both do saturated hydraulic conductivity all the time on soils. I asked them I said, in all the models that are used for monitoring and estimating saturated hydraulic conductivity. Has anybody ever looked at the different clays and see how saturated hydraulic conductivity is impacted by clay speciation. And they I think they both look at each other over email. And they said no, no one's ever at least that we know of reported if you have a soil that has 100% kaolinite versus one that has 100% smectite. We always just think about clay content, right, we always think about clay content we don't necessarily always think about the the actual mineralogy of that clay. So I think there's some some things that we can do in that realm to help everyone. Okay, let's take three different soils. This is a soil north of Williston. It's called the tremble series. It's a taxonomic class is course loamy. It's got mixed mineralogy. It's it's CEC to clay ratio is greater than 0.6 so it's super active it's got calcareous blah blah blah. It's an antisol, but it has smectite and ill like clay, but it's a very deep and well drained. So this is this has got a lot of a lot of course texture in it, a lot of course texture in it. This soil as an example is a good example of where soil flushing might work out really well or soul washing might work out really well course textured soil. It's deep and you have a lot of sand. Okay, so I think it's a as an example this would be something that would be would be something to think about. Compare that to a valor soil which is so common across the state of North as an example. This thing has it's poorly drained. So this is more like a wetland type soil. It's very deep has a lot of clay content is it's mostly smectite high concentrations of smectite high shrink swell. This one to me doesn't seem like a very good candidate for soul washing or flush. It might be good for electro kinetics, because it's going to be wet a lot of fair period of the time, but to get water to move through that high clay, and that's difficult. That's so difficult. And so I think thinking about what types of soils. You're trying to get that the trajectory right you're trying to figure out where in the fact where you're going to get to that that either to 0.8 or 1.2 of what it was before. So let's go down to Texas to down to Kermit, Texas. If there's a soil that would be good for soul washing and soul flushing. This is it. This is has ill I clay. It's non expansive. It's course textured. And there's probably some sort of collegiate on top of it. Right. So everything's sort of like kept in one place. This to me is like the perfect example of all the diagrams that they show about soul washing and soul flushing. This is the type of scenario that would be perfect for it because of the fact you don't have a lot of smectite clay to sort of deal with. And so, okay, so the washing and flushing solutions pros and cons. We talked about our, if you went to Annalise she went through these a little bit but calcium chloride. Well, you don't want to add more chloride if you if at all possible right you're already trying to to clean that up anyway, calcium sulfate. It's available cheap. You can go to the old station and get it, but it's fairly insoluble calcium nitrate at the back end of that the regulation is 10 ppm nitrate as nitrogen. I forgot to put that in there so as nitrogen. We talked about calcium acetate and that stuff is soluble. And it is it is as you saw from Annalise talk, it works really well. And on the backside we're thinking that the acetate will be a good source of carbon for bacteria. Can you use just water. You might be able to if the water in itself has high dissolved solids. If the water has high dissolved solids. If it doesn't you're going to run into what we're going to talk about next is swelling and dispersion. And so, which is really dictated by the clay concept what the mineralogy of the clay. The other one is some sort of ammonium which is a which is a cat ion with an anion, which is likely going to be very soluble in itself. But you're going to run into the problem at the back end of the ammonium in the soil, which can convert to nitrate which are back now to the drinking water standard again. So you don't want to add whatever you add you don't want to make it the bigger problem than what you had before right so. So here's an example of a soil with high concentration of smectite clay in a high concentration and sodium the one on the left in a low electrical conductivity mean the overall salt concentration of this of the solution is low. We'll see if we can get this to go. So this was over the course of about 15 or 20 minutes of dropping that cube into that water. That's what dispersion looks like. So if in fact, when we talked about the electro kinetics, if in fact you do not keep the salt concentration up and that sodium concentration goes really high. This is what you're going to end up with water does not move through this. If I had a column of this soil here and I'll show you in a second, you can keep it here until our next reclamation conference, and it would not change. Water does not move through that dispersed soil. However, if you had something like calcium sulfate gypsum solution, you are both adding the calcium calcium to plus which is counteracting the negative effects of the sodium. And you're also adding a little bit of electrical conductivity. A saturated solution of calcium sulfate is the same electrical conductivity is Gatorade. Exact same. So you can think about this one having Gatorade more electrolytes, which is helping keep the soil flocculate, which also helps keeps us hydrated as well. For a price. This is Annalise soil that she showed the other day. I did this. We've had like eight blizzards and fargos to just pick one, but I did it with the last blizzard. I was in the office, only one there surprise and grad students weren't we're all there, of course, but anyway, that her soil has a has a really high electrical conductivity. This is a Brian contaminated soil, but it has a really high sodium concentration as well. I both of these were topped off to the top with water. And you see the float that I put in there. Over time, this one moved pretty well. Right. It moved really well because of the fact that you had you still had a high electrical conductivity, even though the fact you had a lot of sodium. But as soon as you started to lose the electrical conductivity of that solution, that's when you got soul swelling and dispersion. It's shut off. I guarantee you you could leave it in here for until our next time we're here. And if it none evaporated, it would look exactly like that. And the other one we had calcium acetate mixed with the soil. Not a problem. Okay, calcium was there. You had electrical conductivity, water moved through just fine. Okay, what happens when you have water or do any of these methods work? It's going to be pretty tough. If you have water that's that close to the surface, you're probably in some sort of wetland situation anyway, or at least you're close to it. Landowners are part of federal programs. Part of that federal programs is is a swamp buster where they cannot destroy wetlands. So before you please before you go through that, make sure that that landowner will not get kicked out of the farm program for eliminating that wetland. It's true. It's unfortunate, but but things have to progress in a way because that's the way they get crop insurance as well. So, and I don't know if it would be too impactful or too wise to start digging out soil and start pulling up all that groundwater at the same time and trying to flush it and wash it. Okay. And then again, the delineation is key. So knowing where you're at where your contamination is with that. Okay, I'm going to talk about some of the stuff that Tom just highlighted on a site. Passive and active remediation both happened at the site. To the passive side, they did a flush and pump and then later on they did soil washing. So I'm going to give a high overview of both the site characterization that took place. I'm going to talk about the geology because that's my jam and pros and cons of both options. So for the recent information, there was a 1500 barrel produce water release that happened in May of 2015. It's in the Prairie Potholes region on the northwest corner of the state. The affected media was surface water, groundwater, soil, wildlife, definitely vegetation. So this doesn't quite show the whole site, but surface water that was impacted was that little blue area, which was a stock pond. There's also a stream that heads southeast and there's also a larger lake downstream. One of the first things that's important if you can do it is sample your source. That helps you narrow what analyticals you should run or laboratory tests. This, the source water from this release had 208,000 part per million chloride. There was marginal hydrocarbons and metals, but upon initial sampling at the site. The contaminant concern was sodium and chloride. There wasn't much for metals or hydrocarbons. So those were eliminated as the project went forward. There have been multiple geophysical surveys done the site, both BMS and ERTs. Top photo there's an EM, bottoms ERT. For mid to large size spills, I find that an EM is a great way to figure out your footprint on the spill. ERT helps give three-dimensionally or gives an idea of three dimensions of the spill to figure out your depth. But it's still, EM surveys kind of a heat map. It gives you your parent conductivity. So from there, once you know kind of your surface area, you can go to map out your soil borings for this site. We use both conventional for soil collection or sample collection and did geophysical. Geophysical is really helpful because we were able to figure out there's three water bearing zones in the top 60 feet at the site. From there, you're likely going to have to install some monitoring walls. There were, I think the monitoring wall network was, there was 27 at the peak. We've since abandoned some of those. You got a spill of this size. You probably have to install some piezometers. Those were really helpful for figuring out the energy of groundwater and how fast that contaminant will be migrating. There were, well, I think there was upwards of 17 surface water sample location that had been checked throughout the project. I think that's been scaled back to seven that are sampled quarterly. And then one thing I want to stress is if you, you should develop a sampling plan, whether it's for groundwater or soils and stick to it. If you're going to cut some analytes out that you're going to send for labs, be sure you kind of discuss that maybe with a peer or something because you end up, in some cases, you cut out analytes that later on. But if you're on the project, you wish you would have still been tracking. And then with the project this size, probably going to have to do some sort of biological assessment. I think there's been three now throughout the life of this remediation project. So from the soil boings, we found out we had chloride concentrations exceeding 90,000 part per million and exceeding 20,000 part per million in groundwater. Geology, the fun stuff. So the mapped surface geology from USGS map is coal harbor formation, which is a glacial deposit. It's comprised of 70% glacial till and 25% sands and gravels. That geology, local geology was confirmed with the soil boings performed at the site, except for actually the area in red. That was a pretty highly organic borderline fat clay that is probably the reason why the contaminants stuck there. And then groundwater varied from approximately three and a half to 25 feet depending on where you were at. By the point of release, it was a little deeper, but down there in the flats, it was a shallow was three and a half feet. And it's important to note that there was multiple water bearing zones out there. So based on the site characterization, the responsible party decided to go with a flush and pump system, which was installed in 2016, operated through early 2020. It's kind of hard to see in that picture, but all those white lines covering the contaminated zone are drain tile. There's over 50,000 feet or 10 miles installed, so a lot of pipe. A lot of pipe. The blue marks on there are the sump wells that were collected the drain tile to pull the contamination out. They were also able to pull groundwater too. Throughout the process, there were some official amendment supplied calcium nitrate gypsum. I know they treated with straw too to try and help groundwater infiltrate. There was over 132,000 barrels of water irrigated to the site to try and flush the chlorides. And that was done both by flood irrigation and by sprinklers. And there was approximately 65,000 barrels of water recovered. Which kind of based on some rough calculations. That led to almost 106,000 pounds of chloride removed from soil and groundwater at the site. Fast forward to 2020 insurance company in charge of the spill or not responsible, but in charge of it was not super happy with the timeline. So they decided to come in and basically took it away from the producer and do soil washing. So you can see from the top photo there, the treatment cells were constructed on site with onsite soils. They then put in a synthetic liner to keep fluids within the cells. They installed a leachate collection system to collect any of the fluids that filtered through the soil. So from there, the contaminated soils were excavated, placed in the cells and compacted. They did compact. They had a sheep's foot onsite, which was kind of interesting. I thought they would have left it loose. And then they had three proprietary chemical treatments, meaning it's they do not disclose of what was used. And then they followed it up with a fresh water went fresh water rinse. And then all those foods were collected and sent to a disposal well and to cover the whole area they excavated almost 28,000 yards treated it onsite and put it back. So soil washing before they started that, they I don't know if they performed any onsite investigation. I know some information was turned over from the responsible party to them and they made all their decisions off of that. And I don't even know if they requested any additional. I think they just got some bare minimum info and decided to go with it. So it's it's pretty important, I think that they should have done a little bit more investigating. Some of the issues with both obviously timeline ended up being a problem with flush and pump. But with soil washing, we did some post sampling, and there were pretty high concentrations of calcium, ammonia and nitrogen. So it added more contaminants of concern to the list to deal with as this project goes on. But also effectively double the surface area, as you can see from this impacted area is the dark colored on the bottom photo. Actually, that's water too. But yeah, it probably more than double the surface area. And then yeah, as they as they were excavating as you saw, the groundwater was pretty variable across the site anywhere from the three and a half to 25 so in certain areas they ended up actually getting into groundwater. And that ended up posing a pretty big issue. The other thing is groundwater was still impacted there so even if this soil or even if this washing cleaned up 100% of it you're still putting it back on top of contaminated groundwater. I do feel like it'd be effective in an area where the Vado zone is a lot thicker and you don't have shallow groundwater, because they did end up removing in the one year they ended up removing 62,000 pounds. And that's worth of chloride it took for the project and that's after we'd already been treating it for four years. So if the concentrations were higher, initially washing could have led to even more. I definitely the onsite soils to were just, well, it's not really conducive any sort of remediation with how fat they were and water just doesn't want to move through it but I think in some areas. It could be down in the southwest corner of the state. Once you get out of glacial till country, maybe Sentinel beaut formation. It could be pretty effective. But as of right now, the whole area has been disturbed and put back and we still have some chloride impacts to deal with so I don't know if we're that far ahead and compared to where we would have been if we just kept operating the system to begin with.